The invention relates to a low-flammability shingle and to roofs and roof surfaces made thereof.
Low-flammability shingles have to meet a diversity of requirements. This is achieved by the shingles having a multilayered construction. Known low-flammability shingles which essentially meet the requirements have a laminatelike construction involving a plurality of discrete specialty bitumen and glass fiber web layers. There are also low-flammability shingles which comprise just one heavyweight glass web inliner, so that the above-described multilayered construction is simplified. The aforementioned heavyweight glass web inliners customarily have a basis weight of at least 100 g/m2. The above-described laminatelike construction or the heavyweight glass web inliner provide the shingle, on the one hand, with adequate mechanical stability and, on the other, with high resistance to flying brands and radiant heat.
As well as these properties, low-flammability shingles have to have high form stability, so that they stay free of any deformations which would result in roof leaks even after prolonged use.
Previously known low-flammability shingles either have a laminatelike construction involving discrete specialty bitumen and glass fiber web layers which is relatively costly to realize, or else they comprise heavyweight glass web inliners, which are relatively costly. A further disadvantage is that bitumen adhesion on glass fiber webs is not a straightforward matter. Furthermore, delamination cannot be ruled out, given the different physical properties of the individual layers. In addition to the above-described advantages, it is desirable that the shingles have a high nail pullout resistance, since they are customarily secured on the roof structure by nails.
It is an object of the present invention to provide furtherxe2x80x94simple-to-realizexe2x80x94low-flammability shingles which, on the one hand, meet the fire protection requirements of fire protection standard DIN 4102 Part 7 and fire protection standard xe2x80x9cNordtest Method No. 6xe2x80x9d and, on the other, possess adequate nail pullout resistance. Furthermore, the shingle of the invention shall possess high delamination resistance and improved bitumen adhesion. A further requirementxe2x80x94for economic reasonsxe2x80x94is the omission of a relatively costly glass fiber web inliner.